Cool Your Heels, and Your Tasty Beverage
June 9th, 2011
This is the third installment of the "It's a Dry Heat" series. At the time I wrote the "It's a Dry Heat" blog, I didn't know this was going to be a series, but since there is so much about the desert environment to be taught, figure what the heck. I consider the blog about wearing cotton in the desert as the prequel (for all you Star Wars fans). Anyway, this blog is about evaporative cooling and how you can cool your beverages with a wet wool sock. How is that possible you ask? Well, I will tell you.It is pure science - no mind freakin'. I was told about this trick by an Iraq War vet friend who spend over a year in a desert environment not unlike that of the Arizona desert (aside from being shot at...well then again). Anyway, to be brief...
1. Take a wool sock, Smart Wool works great (cotton socks will also work).
2. Get the sock wet.
3. Put your beverage in the sock- make sure it is in a sealed container such as a soda can, beer can or an 8 oz milk carton (you can't just put a full margarita glass in a sock). This works great for chilling candy bars as well!
4. Hang the sock and wait 2-3 hours. Make sure the sock stays damp and you may have to get it wet a second time depending on the amount of breeze and the dryness of the air (the more humidity, the less effective evaporative cooling is).
5. Remove your beverage from the sock and enjoy the coolness!
How does this work? The process of evaporation happens all the time. Our bodies, for example, perspire in hot weather; through evaporation, the sweat dries and lowers body temperature.
Whenever dry air passes over water, some of the water will be absorbed by the air. That's why evaporative cooling naturally occurs near waterfalls, at rivers, lakes and oceans. The hotter and drier the air, the more water that can be absorbed. This happens because the temperature and the vapor pressure of the water and the air attempt to equalize. Liquid water molecules become gas in the dry air, a process that uses energy to change the physical state. Heat moves from the higher temperature of the air to the lower temperature of the water (your wet sock). As a result, the air is cooler, thus making the beverage surrounded by the cooler air colder as if you put the beverage in the refrigerator. Eventually the air becomes saturated, unable to hold more water, and evaporation ceases, which is why evaporation does not occur in more humid environments.
Still don't believe me, give it a try next time you are in the Arizona desert in late April through late June or the latter part of September. Make sure you have 2 beverages, set them outside for a while to get them good and warm. Put one in the wet sock and the other not, but leaving both outside. After a few hours, crack open each beverage and experience the results for yourself.
Cheers!
